package com.youth.framework.security;

import java.util.Collection;
import java.util.Iterator;

import org.springframework.security.access.AccessDecisionManager;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.authentication.InsufficientAuthenticationException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;

public class MyAccessDecisionManager implements AccessDecisionManager
{
    
    public void decide(Authentication authentication, Object object,
            Collection<ConfigAttribute> configAttributes)
            throws AccessDeniedException, InsufficientAuthenticationException
    {
        if (configAttributes == null)
        {
            return;
        }
        
        // 所请求的资源拥有的权限(一个资源对多个权限)
        Iterator<ConfigAttribute> iterator = configAttributes.iterator();
        while (iterator.hasNext())
        {
            ConfigAttribute configAttribute = iterator.next();
            // 访问所请求资源所需要的权限
            String needPermission = configAttribute.getAttribute();
            // 用户所拥有的权限authentication
            for (GrantedAuthority ga : authentication.getAuthorities())
            {
                if (needPermission.equals(ga.getAuthority()))
                {
                    return;
                }
            }
        }
        // 没有权限让我们去捕捉
        throw new AccessDeniedException("没有权限访问！");
    }
    
    public boolean supports(ConfigAttribute attribute)
    {
        return true;
    }
    
    public boolean supports(Class<?> clazz)
    {
        return true;
    }
    
}
